OK, so. I'm not really the person to ask about your main questions, because I don't particularly focus on government troops. To be quick about that part, yes there were government Outposts in Scotland and the Highlands at the time of the '45 and there were efforts ongoing to subdue the rebellious activities. It's a bit strange to talk about British outposts in the Highlands, since the Highlands were part of the United Kingdoms of England and Scotland and of the nascient British Empire, so I'm going to refer to the "government" as the sitting Hanoverian king in London and "Jacobites" for the rebels. Anyway, after the 1715 Rising, there were efforts to make the Highlands easier to subdue by creating a series of military roads and bridges throughout the area, which would allow for quicker troop access in the event of a rising. Field Marshal George Wade was put in charge of this project and for some time after, these were simply the “Wade’s Roads.” Wikipedia gives a summary of what roads where built where and when here. (As an aside, what is now the Great Highland Way is, in fact, one of the Wade’s Roads.)

Moving on from that, the Wade Roads were also meant to connect the chain of forts along the Great Glen, Fort George, Fort Augustus and Fort William. Fort William is probably the best known, due to being the end of the Great Highland Way and for being the first entry point of Claire Randall on her time-traveling history-shattering arrival in Scotland in the first book of Outlander. The first two of these forts were taken by the Jacobites during the ’45 and Fort William was also unsuccessfully besieged. In the years before the ’45, Wade also organized the first Highland Watch, to indeed police the Highlands, and consisted of loyalist Scots. I don’t focus at all on English involvement in the Risings, so can’t speak to whether there were also English troops present or to the nationality of the officers in all cases—I focus particularly on the Jacobites, and even more so on the Gaelic experience.

Here, though, I have to stop and address some of the misconceptions you seem to have about the nature of the Rising, who participated, and how serious it was. I’m not sure what you consider to be a “large battle,” but I’m guessing here that you’re thinking of Culloden. Keep in mind that the Jacobites’ goals were to capture the seats of government, being Edinburgh in Scotland and London in England (though there was considerable argument about whether to cross to England immediately or to solidify a base in Scotland first). So it was not in their interest to engage with government armies, so much as to avoid them on the march on Edinburgh. At the time, the Commander-in-Chief in Scotland, General John Cope, commanded around 4000 men, but in an attempt to avoid the Jacobite army, marched first to Inverness and then Aberdeen, while leaving Edinburgh mostly undefended. The Jacobites essentially just walked in, but were not able to take the castle itself. That same day, Cope’s troops were disembarking at Dunbar. They arrived to meet the Jacobites on September 20th, drawing up in a strong position in Prestonpans and protected on one side by a marsh. A local farmer’s son convinced the Jacobite General Lord George Murray that he knew a way through the marsh and so, in the middle of the night, the entire Jacobite army was marched around the government army to launch a surprise attack on the other flank at six a.m. Cope’s army was inexperienced and panicked, turning to flee only to be bogged down in the marsh. This meant that the left and right flank of the Jacobite army were able to advance more quickly than the centre and trap Cope’s men in a V. The battle took less than ten minutes, saw Cope lose his entire baggage train, hundreds of men, and over a thousand captured. The Jacobites, on the other hand, only lost around 100 men. Somewhat famously and by a fluke, Cope also managed to arrive before his men at the rallying point, for which he was court-martialled and later acquitted. (This is why we have songs like “Hey Johnnie Cope, Are Ye Waukin’ Yet?”) This can’t fairly be dismissed as “posturing” around Edinburgh—it caused a panic in London. In just a few short months, Charles Edward had arrived in Scotland, raised an army, captured Edinburgh, routed the Government Army, and was now marching on England. At the time, it was also believed that the Jacobites would be getting assistance from abroad and that the English Jacobites would also rise (in reality, it was just the Manchester Regiment and the ships were prevented from landing). At the time, there was a verse of God Save the King which ran:

God grant that Marshal Wade

May, by thy mighty aid

Victory bring.

May he sedition hush,

And like a torrent, rush,

rebellious Scots to crush,

God save the King.

And probably the magnificent overkill of Handel’s See, the Conquering Hero Comes from Judeas Maccabeas, dedicated to Prince William, Duke of Cumberland, after his victory of at Culloden also demonstrates that this was not considered some abstract threat—people were very tangibly relieved.

Moving on, to clarify that the Jacobite Risings were not clan-on-clan warfare, any more than they were limited to the Highlands or were an English-Scottish conflict. You may notice that I refer to the Jacobite army where most texts and contemporary documents would call it the Highland Army—this is a misnomer. In the first chapter of his book The Myth of the Jacobite Clans, Murray Pittock breaks down the difficulty of designating a particular area as “The Highlands”, given modern, historical and geological breakdowns and argues that the more notable distinction at the time was in fact “North of the Tay,” which encompasses not only the Highlands as we would consider them today, but also a much larger region of Scotland than is currently thought of as “Jacobite”. The same book also gives a (n extremely detailed) breakdown of the origins of Jacobite soldiers and demonstrates that, in spite of the moniker of “Highland army” and the perception they were all Gaelic, a very large number actually came from the lowlands or towns and cities, and certainly also came from the merchant class as well as the “desperately poor.” Even a quick look through The Muster Roll of Charles Edward Stuart shows that. You might refer to this comment for a rundown of who fought and why.

Finally, the idea that Charles “took his forces over the drink” is overlooking the aftermath of Culloden. Yes, Charles did ultimately escape and some of his better-born supporters did as well, but very few of the non-noble supporters did. Many were captured, tortured, denied even basic medical care and food for up to two years, when they were ultimately pardoned. Only 47 (if memory serves) were actually executed for their roles in the ’45 and some fairly notable people were released, such as Flora MacDonald, who actually helped smuggle the Prince to freedom. However, the main aftermath of Culloden, the “harrying of the glens” fell on the body of the Jacobite army and onto the Highlanders who were deemed the root of the problem (though, as I have mentioned, this was not the case). In addition to the “no quarter given” orders at Culloden itself, wounded soldiers were hunted to the homes where they took shelter and were killed in their sickbed, often along with those who offered them shelter. Laws were enacted. Laws were passed with the express purpose of ending the ability of the Highlanders (many Gaelic speaking or presumed Gaelic speaking) to make war, use their language, or even remain where they were. You can read more about it here. (If this URL is wrong, let me know and I’ll fix it when I get home. The link is NSFW, so I can’t get it here.)

I hope that answers your questions and helps to clarify the Jacobite Rising of 1745, its participants, importance and aftermath.